The invention concerns a device for carrying cooling water away from the narrow sides of a slab, especially in the secondary cooling system of a continuous casting installation.
When a cast strand or a slab passes vertically through a secondary cooling system, cooling water accumulates in a wedge-shaped region between the guide rollers of the secondary cooling system and the surface of the strand. The cooling water that temporarily accumulates in the wedge-shaped region then typically flows off downward over the narrow sides of the slabs.
A device for collecting and removing cooling water of this type is described, for example, in German Offenlegungsschrift DE 1 558 239. The device disclosed there provides for only a single water drainage device on each narrow side of the slab, and each of these drainage devices is arranged below or at the foot of the secondary cooling system and its guide rollers. A water pipe is arranged downstream of each of the water drainage devices for removing the cooling water picked up by each of the water drainage devices. Since only one water drainage device and water pipe are provided on each narrow side, they each collect the entire amount of cooling water that flows off from the wedge-shaped regions of all guide rollers located at a higher level over the respective narrow sides of the slab. Each of the water drainage devices can be moved towards or away from the associated narrow side of the slab by means of an adjusting device.
However, because it is located only at the foot of or below the secondary cooling system, this previously known device for removing cooling water from the narrow sides of a slab has the disadvantage that the entire amount of cooling water emerging from all of the wedge-shaped regions located at all of the higher levels flows past each unit of area of the given narrow side. Therefore, this results in a nonuniform distribution of the cooling water and of the resulting cooling effect over the length of the narrow side, because more cooling water from more wedge-shaped regions flows past the lower regions of the narrow side than past the higher regions of the narrow side. Precisely in these lower regions of the narrow sides, i.e., at the end of the secondary cooling system, there then exists the danger of undesired overcooling of these regions of the narrow side due to an excessive amount of water per unit area flowing past these regions.
Therefore, proceeding from this prior art, the objective of the invention is to refine a previously known device for carrying cooling water away from the narrow sides of a slab in such a way that overcooling of the edges or lateral surfaces of the slab is prevented.